A government scientist says new data show that women who wore an intrauterine birth-control device called the Dalkon Shield were 5 to 10 times as likely to suffer serious infections as were women who used other IUDs.

The data come from the first study of significant size to relate particular types of IUDs to pelvic inflammatory diseases (PID). These are infections caused when bacteria in the vagina and cervix move into the normally sterile uterus and fallopian tubes and occasionally into the ovaries and abdomen.

Physicians in the United States inserted more than 2.2 million Dalkon Shields in a 3 1/2-year period ending in June, 1974, when reports of pregnancy-related complications led the Food and Drug Administration to request that sales be suspended by the manufacturer, A.H. Robins Co. of Richmond. Robins sold about 2 million more shields abroad before halting sales altogether.

In 1980, citing the risk of a rare type of pelvic infection, Robins also advised physicians to remove the device from women who were not pregnant and had no disease symptoms.

Dr. Howard W. Ory of the Centers for Disease Control said in an interview from Atlanta that the new data "argue strongly that women still wearing a Dalkon Shield have it removed." He said that the number of American women still carrying shields is unknown but that he believes it to be "very small."

A Robins spokesman declined to comment on the new data, pointing out that the study is unpublished. Company officials have said previously that "the Shield, when properly used, is a safe and effective IUD."

Robins has told its stockholders that it and its insurer had paid out $123 million as of last Sept. 30 to dispose of about 4,800 shield legal claims but that 3,200 "pending cases and claims" remained.

Overall, Ory said, the new data show that the risk of pelvic infection appeared to be 8.3 times higher in Dalkon Shield users than in women who used no contraceptive of any kind. In wearers of other IUDs, however, the PID rate was only 1.6 times higher.

Long-term shield use--at least three years--increased the discovered PID risk to 10 times that of other IUDs. Among shield wearers the risk was found to be 15.6 times higher than in women using no contraceptive, as opposed to 1.5 times higher among women who had worn other IUDs, Ory said.

The study was done by Ory, an expert on reproductive health, Nancy C. Lee and George L. Rubin of the CDC and Ronald T. Burkman of Johns Hopkins Medical Institutions in Baltimore.

The four researchers analyzed data from interviews of 622 women who had entered hospitals for treatment after being afflicted by PID for the first time. The controls were 2,369 hospitalized women who said they had never had the disease.

The data were collected at 16 hospitals in nine cities from October, 1976, through August, 1978--long after shield sales ended. A preliminary report in 1981 cited a risk of PID associated with IUDs as a group but did not break down the results by brand.

The shield was the only IUD that used a multi-filament "tail string" to enable a user to be sure the device is still in place and allow possible non-surgical removal by a physician. Tests show that the multi-filament tail string can let bacteria ascend or "wick" between the filaments into the uterus via tiny holes in the nylon sheath encasing it.

The other IUDs in the study--mainly the Copper 7, Lippes Loop, Progestasert and Saf-T-Coil--use unsheathed monofilament strings, which do not have the shield's "wicking" problem.

Ory said the data showed that, with the sole exception of shield users, most of the increased risk of PID in device wearers occurred within four months after insertion. Nearly 86 percent of shield users had carried the device for at least three years. Scientists say the shield's wicking problem worsens as the sheath deteriorates.